Stray Voltage in My Aquarium

Maybe already discussed at length, but here goes anyway -

While trimming some anubias plants in my 40 gallon long this morning with my forearm pretty well immersed in the tank I noticed a feeling pretty much akin to a severe rash. I had not felt this before in this or in other tanks while doing tank cleaning duties including rearranging, egg and rock removal, gravel rearrangement, etc., etc. The fish, themselves, all seemed ok.

I decided to investigate as I suspected a voltage leak. After viewing several YouTube videos I found the attached narrative which was quite helpful and clearly worded -

Stray Voltage in Aquarium: Fix and Detect Stray Electricity in Water

I attached a separate outdoor extension cord to a three prong (grounded) outlet and followed the instructions in the linked attachment. Which was basically the black probe of my multi-tester into the grounded 3rd prong on the extension cord and the tip of the red probe in the water. Yikes! It read about 18.0 to 19.0 V. I then repeated the test by first unplugging my Seachem Tidal 75 filter. Curiously the meter now read about 15.0 V. I then unplugged the Aquatop 250 W heater and the voltage plummeted to 0.1 V The only thing still plugged in that had a possible direct electrical pathway to the water via it's impeller was my AquaClear 70 hang on back filter. Apparently there is some minimal voltage bleed from it, but 0.1 V is certainly much more tolerable to me than 18.0 to 19.0 V. Additionally, what is with the apparent 2.4 V reading I get with the Seachem Tidal 75 when it is the only thing running (besides the light strip and Whisper pump which are both isolated from any form of electrical contact with the water.

Note, my home is about 50 years old and we have a mix of 2 prong and 3 prong outlets, depending upon where remodeling was done which necessitated upgrading to code.

Any comments based upon the experience of others?

Barry Simon

 

Wow! The weird thing is that you had two significant sources of stray voltage... Makes me wonder what I would get with a test on my aquarium--may try this someday. How old are the filter and heater?

 

The heater was purchased when I set up the tank which was in July of 2020, so a bit over a two years old. The Tidal 55 was purchase a few months later to supplement the AquaClear 70, Si it is maybe about 22 months old.

 

Would makes sure everything plugged into 3 prong that way you know it's properly grounded. Not sure on life expectancy of aquatic heaters but know I change out my cheaper ones every year or two had a similar issue electrical with water isn't worth the risk in my opinion

 

I have a question about all of this - Let's say the wall outlet is a properly grounded 3 prong receptacle, but the male plug on the aquarium accessory be it a heater, hang on back filter, etc., etc. is a two blade, does it matter that the wall outlet is 3 prong if the aquarium accessory plug is only two prong? This is in respect to the 3 blade wall receptacle in some way serving as a ground as the accessory itself does not have a ground. Not being an expert, I would think that unless the whole electrical pathway is 3 prong with a grounding port, there is no advantage in respect to voltage leak into the aquarium but there may be an advantage in that a circuit breaker is less likely to be tripped.

Barry